predcom: Refactor more using auto_vec

This patch follows Martin's suggestion at the link[1] to do more
refactorings by:
  - Adding m_ prefix for class pcom_worker member variables.
  - Using auto_vec instead of vec among class pcom_worker,
    chain, component and comp_ptrs.

The changes in tree-data-ref.[ch] is required, without it the
destruction of auto_vec instance could try to double free the
memory pointed by m_vec.

Bootstrapped and regtested on powerpc64le-linux-gnu P9,
x86_64-redhat-linux and aarch64-linux-gnu, also
bootstrapped on ppc64le P9 with bootstrap-O3 config.

[1] https://gcc.gnu.org/pipermail/gcc-patches/2021-June/573424.html

gcc/ChangeLog:

	* tree-data-ref.c (free_dependence_relations): Adjust to pass vec
	by reference.
	(free_data_refs): Likewise.
	* tree-data-ref.h (free_dependence_relations): Likewise.
	(free_data_refs): Likewise.
	* tree-predcom.c (struct chain): Use auto_vec instead of vec for
	members.
	(struct component): Likewise.
	(pcom_worker::pcom_worker): Adjust for auto_vec and renaming changes.
	(pcom_worker::~pcom_worker): Likewise.
	(pcom_worker::release_chain): Adjust as auto_vec changes.
	(pcom_worker::loop): Rename to ...
	(pcom_worker::m_loop): ... this.
	(pcom_worker::datarefs): Rename to ...
	(pcom_worker::m_datarefs): ... this.  Use auto_vec instead of vec.
	(pcom_worker::dependences): Rename to ...
	(pcom_worker::m_dependences): ... this.  Use auto_vec instead of vec.
	(pcom_worker::chains): Rename to ...
	(pcom_worker::m_chains): ... this.  Use auto_vec instead of vec.
	(pcom_worker::looparound_phis): Rename to ...
	(pcom_worker::m_looparound_phis): ... this.  Use auto_vec instead of
	vec.
	(pcom_worker::cache): Rename to ...
	(pcom_worker::m_cache): ... this.  Use auto_vec instead of vec.
	(pcom_worker::release_chain): Adjust for auto_vec changes.
	(pcom_worker::release_chains): Adjust for auto_vec and renaming
	changes.
	(release_component): Remove.
	(release_components): Adjust for release_component removal.
	(component_of): Adjust to use vec.
	(merge_comps): Likewise.
	(pcom_worker::aff_combination_dr_offset): Adjust for renaming changes.
	(pcom_worker::determine_offset): Likewise.
	(class comp_ptrs): Remove.
	(pcom_worker::split_data_refs_to_components): Adjust for renaming
	changes, for comp_ptrs removal with auto_vec.
	(pcom_worker::suitable_component_p): Adjust for renaming changes.
	(pcom_worker::filter_suitable_components): Adjust for release_component
	removal.
	(pcom_worker::valid_initializer_p): Adjust for renaming changes.
	(pcom_worker::find_looparound_phi): Likewise.
	(pcom_worker::add_looparound_copies): Likewise.
	(pcom_worker::determine_roots_comp): Likewise.
	(pcom_worker::single_nonlooparound_use): Likewise.
	(pcom_worker::execute_pred_commoning_chain): Likewise.
	(pcom_worker::execute_pred_commoning): Likewise.
	(pcom_worker::try_combine_chains): Likewise.
	(pcom_worker::prepare_initializers_chain): Likewise.
	(pcom_worker::prepare_initializers): Likewise.
	(pcom_worker::prepare_finalizers_chain): Likewise.
	(pcom_worker::prepare_finalizers): Likewise.
	(pcom_worker::tree_predictive_commoning_loop): Likewise.

1 files changed, 2 insertions, 2 deletions

diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c
index 210ac28..b6f7828 100644
--- a/gcc/tree-data-ref.c
+++ b/gcc/tree-data-ref.c
@@ -6208,7 +6208,7 @@ free_dependence_relation (struct data_dependence_relation *ddr)
    DEPENDENCE_RELATIONS.  */
 
 void
-free_dependence_relations (vec<ddr_p> dependence_relations)
+free_dependence_relations (vec<ddr_p>& dependence_relations)
 {
   for (data_dependence_relation *ddr : dependence_relations)
     if (ddr)
@@ -6220,7 +6220,7 @@ free_dependence_relations (vec<ddr_p> dependence_relations)
 /* Free the memory used by the data references from DATAREFS.  */
 
 void
-free_data_refs (vec<data_reference_p> datarefs)
+free_data_refs (vec<data_reference_p>& datarefs)
 {
   for (data_reference *dr : datarefs)
     free_data_ref (dr);